A standard bag-making machine has a transport unit for feeding a leading end of the web in a transport direction to a cutting/welding station provided with tools for transversely welding the web and cutting a bag from the leading end of the web. Each such bag cut from the web is stacked and blocked downstream in the direction from the station. A bag-pulling device between the station and the stacker/blocker has an endless drive strand having a pair of stretches extending vertically across a path of the bag between the station and the stacker/blocker. Respective horizontally extending deflector rods carried on the stretches are vertically displaceable therewith, each extend along a respective axis, and each have an outer surface engageable with the web. The stretches of the strand are oppositely displaced to bring the surfaces of the rods into engagement with opposite faces of the bag and thereby pull the bag down and out of the cutter/welder.
Thus once the cutter/welder is closed and pinching the upstream end of the bag, the pulling device can move the bag down to skewer it on heated centering pins of the stacker/blocker while at the same time pulling the upstream end of the bag out of the cutter welder, either just pulling it out from between the jaws or pulling it off the downstream end of the web. During this movement the bag, typically made of a flexible clear thermoplastic like polyethylene, slides over the rod or rods of the pulling device. The friction between the rod and the bag can be sufficient to deform or even tear the bag, and surface imperfections or dirt on the rod can score the bag sliding over it. The solution to this problem is to cycle the machine slowly, but obviously this is not ideal for the mass production of a very cheap consumer item in that it elevates unit cost.